Gender Fluid is a gender identity best described as a dynamic mix of boy and girl. A person who is Gender Fluid may always feel like a mix of the two traditional genders, but may feel more boy some days, and more girl other days.
Being Gender Fluid has nothing to do with which set of genitalia one has, nor their sexual orientation.

A genderfluid person is someone who fluctuates between more than one gender, or between having a gender and not having one. They do not stick to one gender, or lack thereof, for their entire life. It is not related to a person's genitalia, nor their sexual orientation.

Eri identified as a boy last week, a girl yesterday and is agender today. This makes them genderfluid.

An individual who is genderfluid experiences their sense of gender identity shift around the spectrum. They may feel like a boy one day, a girl another, or neutral, or everything at once, or nothing, or something different entirely. This is a completely normal gender identity; being genderfluid is not a mental illness. Gender has nothing do with genitals.

Being genderfluid can be hard, because there are days when I love my body, and days where I just wish it would disappear.

One day you wake up and you feel more femine or masculine. Commonly called "attention seekers" or that they "made up their gender" but no. Is a minority in the trans community along with gender queer and they get alot of hate for it.

(Female genitalia)Gender fluid: Hey guys, I just want to tell you that I am gender fluid! Please use they pronouns for me.
Person:lol, attention seeking fag! Look in your pants! That is your gender you fucking retard

Someone whose gender changes over time. Does not necessarily have to be a boy or girl, can be a mix of the two, neither, or something else entirely. Often confused for having a fluctuating gender presentation, or fluctuating levels or femininity/masculinity/androgyny.